The Bone Morphogenetic Protein (BMP) family of secreted signaling molecules directs the development of multiple organs and tissue types at various stages in embryogenesis, and is implicated in congenital and adult diseases. Enormous insights into the physiologic roles of BMP signaling have been gained through their study in model organisms, which have vastly enhanced our understanding of human development and disease. Here the nature of the BMP signaling complex will be explored that functions during gastrulation to pattern tissues along the vertebrate dorsal-ventral axis. The long-term goal is to understand the molecular basis for the requirement for multiple ligands and receptors to transduce BMP signaling. Second the coordination of patterning along the dorsal-ventral and anterior-posterior axes will be investigated, testing the hypothesis that the signaling pathways that regulate patterning of the anterior-posterior axis also regulate temporally the action of the BMP activity gradient. It is postulated that this coordinate regulation couples the patterning of these two axes, and results in BMP activity acting progressively over time along the anteriorposterior axis to pattern dorsal-ventral tissues. Lastly, the molecular nature and contributions of a new recessive dorsalized, maternal-effect mutant gene, will be studied, to maximize our understanding of the genetic regulation of BMP signaling in development and disease through loss-of-function studies. Thus it is critical to identify and study all the genetic players in this process.